Heads of dodgy enterprise exploit loss (6)
I believe the answer is:
defeat
'loss' is the definition.
(I've seen this in another clue)
'heads of dodgy enterprise exploit' is the wordplay.
'heads of' indicates taking the first letters.
'exploit' becomes 'feat' (synonyms).
The first letters of 'dodgy enterprise' is 'de'.
'de'+'feat'='DEFEAT'
(Other definitions for defeat that I've seen before include "Overthrow" , "failure" , "Beat, win against" , "Gain victory over" , "Overwhelm" .)